This invention relates generally to poured concrete wall systems and, more particularly, concerns a method and apparatus for forming insulated concrete walls.
Concrete walls can be formed in various ways. Some are constructed from concrete blocks on footings, some can be made from prefabricated members, and others can be formed by pouring or pumping in uncured concrete between rigid forms. The wall forms are generally planar structures and typically are made of wood, aluminum, steel, or combinations of these materials. For poured walls, two series of coplanar wall forms are held in a spaced apart, generally parallel relationship to create the cavity which will form the concrete wall. The wall forms are typically held in the correct spaced-apart relationship by a series of retaining ties extending between the form assemblies. The retaining ties commonly include holes formed in each end whereby pins are used to join adjacent coplanar forms together. Once the wall forms are in place, concrete is poured into the cavity between the forms and, after the concrete has cured, the forms are disassembled for reuse. The protruding ends of the ties are then broken off.
Poured concrete walls have many benefits over other types of concrete walls. They can be quickly constructed, are relatively easy to construct, are versatile, and durable. One drawback of all concrete walls however, is that they are poor insulators. A typical concrete wall has an insulating xe2x80x9cRxe2x80x9d value of approximately 1.0.
To improve the insulating qualities of concrete walls, several methods have been developed for incorporating polystyrene sheets within the concrete wall, or on one or both exterior surfaces of the concrete wall. A concrete wall with 2.5 inches of polystyrene insulation on one side has an insulating xe2x80x9cRxe2x80x9d value of approximately 13.0. Similarly, a concrete wall with 2.5 inches of polystyrene insulation on both exterior surfaces of the wall has an insulating xe2x80x9cRxe2x80x9d value of approximately 26.0.
Present methods of insulating concrete walls, however, suffer from the drawback of adding considerable time and labor to construct the concrete wall. One known method in particular uses special parallel foam sheets held together by metal members. This system is difficult and time consuming to set up, and requires additional external supports to prevent the foam walls from bulging due to the weight of the concrete. Another drawback of some insulated concrete wall systems is that they require unique and unconventional wall forms. This also can add additional time, labor and, ultimately, cost to the finished concrete wall.
Accordingly, it is an object of the present invention to provide an improved insulated concrete wall system and method. It is another object of the present invention to provide an insulated concrete wall system using conventional wall forms.
Another object of the present invention is to provide an insulated concrete wall having an exterior surface which readily accepts fasteners in order to attach additional materials to the wall.
According to the present invention, the foregoing and other objects and advantages are attained by an insulated concrete wall structure having a concrete wall with opposing wall surfaces. The concrete wall has several vertically and horizontally spaced wall ties imbedded within it. Positioned between the vertically spaced wall ties are a series of elongated retaining strips such that the retaining strips are substantially parallel to the wall surface. Insulating panels such as polystyrene foam boards are located between the horizontally spaced wall ties and retained in position by the retaining strips. In one aspect of the invention, each insulating panel has a groove formed along its vertical edge for receiving and engaging the elongated edge of the retaining strips.
An advantage of the present invention is that an insulated concrete wall can be readily formed using conventional wall forms in approximately the same amount of time as conventional uninsulated poured concrete walls. The present invention also provides and insulated poured concrete wall which is less expensive than known insulated concrete wall systems.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and dependent claims, an upon reference to the accompanying drawings.